1. Field
The present disclosure relates to a circular stitching device for a sewing machine, which executes a circular stitching while a workpiece cloth is rotated about a cloth-fixing pin having passed through a workpiece cloth at a lateral position spaced away from a needle point.
2. Related Art
In execution of a circular stitching with use of a sewing machine, a circular stitching device fixed with a cloth-fixing pin is conventionally attached to the sewing machine, and a workpiece cloth is fixed at a single point spaced away from a needle position. A needlebar to which a sewing needle is attached is vertically moved while the workpiece cloth is turned about the cloth-fixing pin by feeding cloth by a feed dog, whereby the circular stitching is executed.
For example, Japanese Utility Model Application Publication No. JP-U-H04-103875 (hereinafter “patent document 1”) discloses a circular pattern stitching device used in the above-described circular stitching. The disclosed circular pattern stitching device comprises a fixing member which is adapted to be fixed to a cloth table of a sewing machine and a support which is mounted on the fixing member so as to be slidable in a predetermined direction. The support is provided with a moving member which has a pin hole and is slidable in a predetermined direction. In execution of circular stitching, the support and the moving member are slid according to a size of a circle to be stitched, so that the location of the circular stitching device is adjusted. Subsequently, the cloth-fixing pin is inserted through the pin hole of the moving member from above so as to fix the workpiece cloth, thereby holding the workpiece cloth.
In the circular stitching device of patent document 1, however, the pin hole of the moving member is hidden from the user's sight below the underside of the workpiece cloth when the cloth-fixing pin is inserted through the pin hole. Accordingly, the user needs to insert the cloth-fixing pin through the pin hole with the cloth-fixing pin having been inserted through the workpiece cloth while looking into the space under the workpiece cloth. Thus, a work for fixing the cloth is difficult to carry out.
On the other hand, for example, Japanese Utility Model Application Publication No. JP-U-H04-375 (hereinafter “patent document 2”) discloses a circular stitching instrument in which the cloth-fixing pin is mounted on the instrument body so as to be directed upward but not downward. More specifically, the circular stitching instrument comprises a pin support plate having an upwardly directed cloth-fixing pin and a movement block plate formed with three movement block holes. The pin support plate is attached to any one of the movement block holes, whereby the cloth-fixing pin is adjusted to the center of a circle to be stitched. According to this circular stitching instrument, the pin support plate is fitted into any one of the movement block holes after the cloth-fixing pin has been passed through the workpiece cloth in accordance with the center of the circle to be stitched. As a result, the cloth-fixing pin (the pin support plate) can be attached to the movement block plate more easily.
However, the pin support plate plays or gets rickety when a fit clearance between the movement block hole and the pin support plate is increased in order that the pin support plate may be attached to and detached from the movement block hole more easily. As a result, there is a possibility that a stitch end position may be displaced from a stitch start position. When the fit clearance is reduced so that the pin support plate is prevented from getting rickety, the pin support plate is attached to or detached from the movement block hole with increasing difficulty. Furthermore, since the pin support plate is attached to the movement block plate while the cloth-fixing pin is directed upward on the movement block plate, there is a possibility that the user or the like may touch the pin point with his/her finger tip.